Armadillo is a C++ linear algebra library (matrix maths) aiming towards a good balance between speed and ease of use. The API is deliberately similar to Matlab's. Integer, floating point, and complex numbers are supported, as well as a subset of trigonometric and statistics functions. Various matrix decompositions are provided through optional integration with LAPACK and ATLAS numerics libraries. A delayed evaluation approach, based on template meta-programming, is used (during compile time) to combine several operations into one and reduce or eliminate the need for temporaries.

OGLplus is a header-only library that implements a thin object-oriented facade over the OpenGL (version 3 and higher) C-language API. It provides wrappers that automate the resource and object management and make the use of OpenGL in C++ safer and easier.

libcsdbg is a C++ exception stack tracer. When an exception is thrown, caught, and handled, libcsdbg offers the tools to create and process the exception stack trace, the path the exception has propagated up the call stack, unwinding it up to the section were it was handled. The traces are detailed with demangled function signatures and additional addr2line information (the source code file and line from which each function was called). libcsdbg can use all the well-known objective code file formats (a.out, elf, coff, ecoff, etc.) and can easily be used as the base for your own instrumentation code. libcsdbg transparently loads the symbol tables of the chosen dynamic libraries and of the executable, demangles function symbols to complete signatures, and binds function names to runtime addresses (even for the DSO symbols).

neon is an HTTP and WebDAV client library for Unix systems, with a C language API. It provides high-level interfaces to HTTP/1.1 and WebDAV methods, and a low-level interface to HTTP request/response handling, allowing new methods to be easily implemented.

HC-SR04 Ultrasonic Arduino Library is specifically for the HC-SR04 ultrasonic sensor. It features timing, metric conversion, and standard deviation methods, plus a few support methods. It is written in C++ to conserve the namespace. The conversion formula can be easily modified to optimize the accuracy of conversion at different distances for inches and centimeters. Multiple buffers of different lengths can be created for determining standard deviation.

libpfrng is a userspace library which provides a high-quality but slow random number generator based on CPU timing jitter. It passes Diehard, FIPS, NIST, and entropy tests, and is high-rated by CAcert RNG test.

libxmp is a module player library which supports many mainstream and obscure module formats, including Protracker MOD, Scream Tracker III S3M, and Impulse Tracker IT. Possible applications for libxmp include standalone module players, module player plugins for other players, module information extractors, background music replayers for games and other applications, module-to-mp3 converters, etc.

libquickmail is a library intended to give C/C++ developers a quick and easy way to send email from their applications. It supports multiple To/Cc/Bcc recipients and multiple MIME attachments without size limitation. It uses libcurl for SMTP communication, but a light version is also included without the libcurl dependancy. The library can also be used to just create a multipart MIME message body. It also comes with a command line application for sending mail (with optional attachments).